Re: [linux-pm] driver power operations (was Re: suspend2 merge)

On Friday, 27 April 2007 16:49, Johannes Berg wrote:
On Fri, 2007-04-27 at 16:39 +0200, Johannes Berg wrote:

Good point. Though if we go for passing the interrupt-enable setting as
an argument then many drivers will have the same
"if (irqs_disabled()) return" code. Hm. I guess passing it isn't even
strictly necessary.

Eh, the point I actually wanted to make is that many drivers don't care
for the irqs disabled case and would have to add code to exclude it.

I think we can use 'stages' and pass them as arguments to the functions.

In that case we can have two callbacks for the hibernation (I'd prefer to say
'hibernation' instead of 'suspend to disk' from now on), one 'quiesce' callback
and one 'activate' callback that can be called many times in one
snapshot/restore cycle with different arguments, for example:

quiesce(PREPARE) -- that may be needed for drivers that allocate much memory
before quiescing devices (if any)
...
quiesce(PRE_SNAPSHOT)
...
quiesce(PRE_SNAPSHOT_IRQ_OFF)
...
activate(POST_SNAPSHOT_IRQ_OFF)
...
activate(POST_SNAPSHOT)
...
activate(FINISH)

etc.

Greetings,
Rafael
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Relevant Pages